"The very worst thing for Katie- according to former members of Sea Org, the church’s holy order, that I’ve been in touch with in the past few days- will be the terror that her own secret thoughts about sex and love and despair may come out into the open," Sweeney wrote in a column for "The Independent".

According to Sweeney, the Church of Scientology records confessions of its members using an E-meter "for technical purposes"; they are then kept within the organization.

Though spokespeople for Scientology have dismissed claims the recordings will be offered to the public when a member is excommunicated, the private details of former Sea Org member Amy Scobee's love life were somehow released.

"She must be very afraid, but I can’t help feeling that what she is doing is right and brave and good," Sweeney wrote.

The British journalist had an experience with Scientology five years ago after documenting the religion and he states that Holmes might face the same treatment.

"Private investigators whom I believe were working for the Church chased me around the streets of LA, invaded my hotel at midnight and put me under surveillance at breakfast. Strangers spied on my wedding and knocked on the doors of my neighbours," he wrote.

"They spied on me in Britain. I’ve heard from a solid source that the Church hired a team of private eyes here. I know the name of the company and have asked the House of Commons select committee on private investigators to look into it, with no success."

Sweeney has one bit of advice for Holmes now that she’s lost one of Scientology’s greatest allies (her ex husband).

"Do not doubt the power of the Church of Scientology," Sweeney warned in his column. "I want to write a book about my experience of the Church, and thus far every single publisher we have approached has turned me down."